Comet Panstarrs © ingólfur bjargmundsson
( iceland ) Although a line of burnt orange along the horizon marks where sunset has already occurred, most of the light in this image still comes ultimately from the Sun. High in the sky the bright disc of the Moon is shining with reflected sunlight, while a tiny smudge above the sea is sunlight reflecting from the dust and gas in the tail of Comet Panstarrs. Even the aurora’s ghostly curtains of glowing gas are ultimately powered by the ‘solar wind’ of subatomic particles given off by the Sun. Only the stars shine with their own light.